Subject: packets of multiple users sent over the same TCP/IP session

From: Haim Rochberger <[email-masked]>
Date: Sun, 25 Jan 2004 15:42:28 +0200

Hi,

I am looking for any protocol or type of protocol/application that runs over
TCP/IP, and that packets of that same session "belong" (i.e. either destined
or sourced) to/by 
more then one subscribers (meaning that each packet belongs to one
subscriber, but there are a some packets that belong to subscriber A, some
to B, etc.).
 
I am not talking about tunneling protocol, as in their case the internal IP
is the identity of the subscriber, but I am talking about protocols that the
identity of the subscriber 
resides at the higher level, like the application layer, and the muxing
between the packets to subscribers can be done only if you understand the
protocol at that high level.

An example for such a protocol is SMPP that is used for sending SMS messages
of different subscribers on the same TCP/IP session
between the SMSC and the application server. There, the subscriber identity
is embedded in the SPMM protocol (above the TCP/IP).

I will appreciate your help as it will help in making a better design
decisions.

Yours,

Haim.

---

From: [email-masked]
Date: Sun, 25 Jan 2004 11:42:31 -0500

> I will appreciate your help as it will help in making a better design

Hmm.. been a while since I've had to post this. ;)

The first thing you want to do is take a step *back* from the problem, and ask
yourself what problem you're trying to solve via this multiplexing.  You
already said you didn't want to use tunneling, but at the same time you gave us
insufficient information to know if SMPP or anything similar is applicable to
your problem. With the information you gave, it's likely many will fear to give
you any really useful answers for fear of sending you in a totally useless
direction.

For all I know, HTTP pipelining may be a solution to your problem - in that
scenario, you have in-flight packets for multiple HTTP requests (read
"subscribers") active at the same time.  On the other hand, although it meets
the requirements you stated, it's almost certainly not the right answer.  But
not knowing what problem you're trying to solve, it's hard to say.

Basically, you need to make sure that what you have in your hand is a nail
rather than a screw *before* you start selecting hammers....

---

From: Markku Savela <[email-masked]>
Date: Sun, 25 Jan 2004 20:33:45 +0200

> From: Haim Rochberger <[email-masked]>

> I am looking for any protocol or type of protocol/application that
> runs over TCP/IP, and that packets of that same session "belong"
> (i.e. either destined or sourced) to/by more then one subscribers
> (meaning that each packet belongs to one subscriber, but there are a
> some packets that belong to subscriber A, some to B, etc.).

Sort of like TCP connections between IRC servers, messages of
different clients over the same connection?

---

From: "Randall R. Stewart (home)" <[email-masked]>
Date: Tue, 27 Jan 2004 13:15:21 -0600

Haim:

If I understand your problem correctly I would think
the closest thing to this is what sigtran has done with
SS7 over IP..

They use SCTP and use its stream feature to avoid
head of line blocking for the various calls.. I am not
sure if they put each call in its own stream or each SLS
in its on stream.. either way would work.

In there case they have

xUA
------
SCTP
------
IP

Where xUA is their User Adaption layer.. and the X
being one of MTP2/MTP3 or S

Depending on what levels of the SS7 stack they are adapting

R

Haim Rochberger wrote:

> runs over TCP/IP, and that packets of that *same* session "belong" 
> (i.e. either destined or sourced) to/by
> more then one subscribers (meaning that each packet belongs to *one* 
> subscriber, but there are a some packets that belong to subscriber A, 
> some to B, etc.).
>  
> I am not talking about tunneling protocol, as in their case the 
> internal IP is the identity of the subscriber, but I am talking about 
> protocols that the identity of the subscriber
> resides at the higher level, like the application layer, and the 
> muxing between the packets to subscribers can be done only if you 
> understand the protocol at that high level.
>  
>  
> An example for such a protocol is SMPP that is used for sending SMS 
> messages of different subscribers on the same TCP/IP session
> between the SMSC and the application server. There, the subscriber 
> identity is embedded in the SPMM protocol (above the TCP/IP).
>

-- 
Randall R. Stewart
815-477-2127 (office)
815-342-5222 (cell phone)

---

From: Michael Richardson <[email-masked]>
Date: Tue, 27 Jan 2004 17:27:08 -0500

-----BEGIN PGP SIGNED MESSAGE-----

>>>>> "Haim" == Haim Rochberger <[email-masked]> writes:
    Haim> I am looking for any protocol or type of protocol/application that
    Haim> runs over 
    Haim> TCP/IP, and that packets of that same session "belong" (i.e. either
    Haim> destined or sourced) to/by more then one subscribers (meaning that
    Haim> each packet belongs to one subscriber, but there are a some packets
    Haim> that belong to subscriber A, some to B, etc.).

  Examples that come to mind:
	   1) NFSv3 over TCP	(one TCP connection per mount)

	   2) SMTP		(multiple users' transactions per session)

	   3) persistent HTTP from a www proxy.
	      (I'm not really sure if this is really done)

]       ON HUMILITY: to err is human. To moo, bovine.           |  firewalls  [
]   Michael Richardson,    Xelerance Corporation, Ottawa, ON    |net architect[
] [email-masked]      http://www.sandelman.ottawa.on.ca/mcr/ |device driver[
] panic("Just another Debian GNU/Linux using, kernel hacking, security guy"); [